化简（2/3a^4b^7-1/9a²b^6）÷（-1/3ab³）²

化简（2/3a^4b^7-1/9a²b^6）÷（-1/3ab³）²
化简（2/3a^4b^7-1/9a²b^6）÷（-1/3ab³）²

化简（2/3a^4b^7-1/9a²b^6）÷（-1/3ab³）²
原式=a²b^6(2/3a²b-1/9)/(1/9a²b^6)
=9×(2/3a²b-1/9)
=6a²b-1